https://www.enotes.com/homework-help/who-osvaldo-cruz-book-called-moster-by-walter-dean-78207
Hope this link helps but if you don’t want to do se any link or take a look at them, I will have the copied information in my answer:
As was mentioned in the previous post, Osvaldo Cruz is a fourteen-year-old boy who participates in the robbery of the convenience store. He is a member of the street gang known as the Diablos and is portrayed as an unreliable witness throughout Steve Harmon's trial. Osvaldo initially criticizes Steve for attempting to act like a thug before they agree to help Bobo and James King rob the store. Osvaldo's job during the robbery is to stand outside of the convenience store and slow down anybody attempting to chase after Bobo and James King as they flee the store. While Osvaldo is on the witness stand, he testifies that he only participated in the robbery because Bobo threatened to harm him and his family. Osvaldo also implicates Steve Harmon by testifying that Steve's job was to be the lookout. Petrocelli, Steve's lawyer, portrays Osvaldo as an unreliable witness who is simply testifying in order to receive a lighter sentence. Following the trial, Steve mentions that Osvaldo was arrested for stealing a car and sent to a reformatory.
Osvaldo Cruz is a fourteen year old boy the prosecution uses as a witness against King and Harmon in the murder/robbery trial. Cruz, during his testimony, states that his involvement in the trail only happened because Bobo told him that if he did not help in the robbery he would cut him. Cruz also stated that Bobo threatened to do the same to his (Cruz's) mother. Cruz states that Bobo had the robbery all planned out. That he (Bobo) and King would go in to rob the store and that Cruz simply had to slow anyone down that came out after them. Cruz states:
All I had to do was to slow anybody down who came out after them. I was going to push a garbage can in front of them.
Cruz also testifies that Steve Harmon was going to be the look-out. After his testimony regarding the crime, Steve's lawyer (O'Brien) gets Cruz to admit that he belongs to a gang called the Diablos and that he cut someone in the face as his initiation into the gang.
Hope this info helped I haven’t read this book but I think that this information can give you hints on the character’s character traits.
